<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .m1{
				width: 300px;
				height: 300px;
				border: 1px solid red;
				 position: relative;
			}
			.m2{
				width: 200px;
				height: 200px;
				border: 1px solid blue;
				position: absolute;
				margin-left: 150px;
				left: -101px;
}
    </style>
</head>
<div class="m1">
    <div class="m2"></div>
</div>

<body>
    
</body>
</html>